Cell-free DNA analysis in preimplantation genetic testing

Detection of chromosomal aneuploidies and monogenic disorders in preimplantation embryos is essential for selecting the best embryo for transfer during in vitro fertilization (IVF) to achieve a healthy pregnancy. Preimplantation genetic testing (PGT) is typically performed on preimplantation embryos to select a genetically normal embryo for transfer. A trophectoderm (TE) biopsy is necessary for PGT; this is an invasive procedure to the embryo that requires specialized equipment and highly trained embryologists, resulting in high costs associated with IVF treatment. Moreover, the biopsy procedure may increase the likelihood of developing pregnancy complications such as preeclampsia and hypertensive disorders. Therefore, there is a need for non-invasive embryo screening strategies. The presence of cell-free DNA (cfDNA) in the embryo culture medium presents an opportunity to screen for genetic abnormalities. cfDNA is released by embryos in the latter stages of preimplantation development, and its analysis has been proposed as a non-invasive approach for PGT. Here, we review studies reporting concordance rates between cfDNA and TE biopsies, or whole blastocysts (WB), in couples undergoing PGT. Non-invasive PGT results are promising for aneuploidy detection, with some early evidence of successful clinical application. Further research is required to explore its application for the detection of structural rearrangements and monogenic disorders.

P-542 Accuracy of Rapid Prenatal Testing by 24-chromosome analysis using Next Generation Sequencing

Study question

What is the accuracy of NGS versus QF-PCR in the Rapid Prenatal Testing?

Summary answer

NGS seems to be a reliable alternative for Rapid Prenatal Testing and expand the aneuploidy screening to all 24 chromosomes.

What is known already

As part of the prenatal care, whenever an invasive testing is needed, rapid prenatal analysis is performed to rule out the most common aneuploidies (i.e., trisomy for chromosomes 13, 18 and 21), using FISH or QF-PCR. Some studies describe the use of the NGS as an alternative to detect genetic alterations in the DNA from amniocytes or chorionic villus sampling (CVS) in Prenatal Genetic Testing.

Study design, size, duration

This research study evaluates the accuracy of NGS analysis for Rapid Prenatal Testing comparing the results with gold standard techniques. A total of 32 amniotic fluid samples clinically analysed by karyotype (n = 3) or QF-PCR (n = 29) were used as reference resulting in: normal male (n = 3); normal female (n = 9); trisomy 13 (n = 3); trisomy 18 (n = 5; one by karyotype); trisomy 21 (n = 10; one by karyotype); partial trisomy 3q26q26/partial monosomy 5p13p15.33 (n = 1; by karyotype); and triploid XXY (n = 1).

Participants/materials, setting, methods

All 32 samples were analysed using an NGS platform validated for PGT-A (Preimplantation Genetic Testing for aneuploidy). Ion ReproSeq™ PGS kit was used for library preparation, Ion Chef™ and Ion S5 System instruments for sequencing and Ion Reporter software for data analysis (Thermo Fisher Scientific, USA), with a proprietary bioinformatics pipeline (v2.0) for the analysis of 24-chromosome aneuploidies and partial duplication/deletions (≥10Mb). NGS results were compared with the reference QF-PCR/Karyotype results for accuracy evaluation.

Main results and the role of chance

When comparing NGS versus QF-PCR/Karyotype results, we observed a 100% concordance for the detection of trisomy 13 (3 out of 3 samples), trisomy 18 (5 out of 5 samples), trisomy 21 (10 out of 10 sample) and partial trisomy 3q/partial monosomy 5p (1 out of 1 sample). We did not identify false positives for any of the chromosomes in which comparison could be done as they were analysed in the reference samples (chromosomes 13, 18, 21, X and Y for QF-PCR reference samples, and all 24 chromosomes for Karyotype reference samples). In one of the samples, the triploid XXY, the NGS profile for the sex chromosomes was compatible either with a normal male result with maternal cell contamination or with a triploid XXY result, and was finally classified as non-informative for NGS.

Limitations, reasons for caution

The NGS cannot identify deletions/duplications <10Mb and mosaicism <30%. The platform used cannot identify some types of polyploidies, therefore, additional analysis (Short Tandem Repeats, karyotype, or SNP-arrays) when normal results are needed. However, improvements in technology that are currently underway will solve this limitation.

Wider implications of the findings

Based on the experience gained since the implantation of the NGS method for the characterization of the chromosomal status of DNA samples, the use of the NGS platform and protocols for the rapid prenatal test samples has as benefit to expand the screening analysis to all 24 chromosomes.

Trial registration number

Not applicable

Attitudes Toward Inclusion and Benefits Perceived by Families in Schools with Students with Autism Spectrum Disorders

The aim of this study was to find out about attitudes toward inclusion and benefits perceived by families with children enrolled in schools attended by students with ASD at different educational stages (from kindergarten to high school). 323 families of classmates of students with ASD from different educational stages of 16 mainstream schools participated. The analysis of the attitudes, perceived benefits, relationship with the teacher, and relationship with the school was carried out through questionnaires. The results show positive attitudes toward the inclusive education of students with ASD in all families, but especially among families of children with SEN. All the families identified the benefit of inclusion. Attitudes are related to collaboration with the school and satisfaction with teachers.

O-115 Parental whole-exome sequencing allows the discovery of genetic causes of extreme IVF phenotypes such as oocyte/embryo developmental arrest and recurrent low fertilization

Study question

Do whole-exome sequencing (WES) data from infertile women provide valuable information for the discovery of genes/pathways involved in extreme IVF phenotypes, i.e. oocyte/embryo developmental arrest?

Summary answer

The development of a specific bioinformatic WES pipeline revealed known and new candidate genes/pathways for isolated oocyte/embryo developmental failure,providing the foundation to scale up research.

What is known already

The use of IVF has made it possible to identify extreme and isolated infertility phenotypes such as recurrent low oocytes maturity (LMR), recurrent low fertilization rate (LFR), or preimplantation developmental arrest (PDA) that would remain concealed in natural conception attempts. Recent applications of WES in families with such extreme adverse IVF phenotypes have led to the discovery of new genes and pathways affecting unique functions of gametes and exclusive mechanisms necessary for early embryo development. Here, we apply a tailored bioinformatic approach to WES from women displaying extreme IVF phenotypes to discover new causative genes/pathways involved in unexplained infertility.

Study design, size, duration

Twenty-two infertile consanguineous women(December 2018-September 2020) suffering from long-term unexplained infertility. Eight cases were classified as PDA (<20% normally developed embryos in > 2 IVF cycles), 8 as LMR (<20% mature oocytes in > 2 IVF cycles), 4 as LFR (<20% of normally fertilized oocytes in > 2 IVF cycles). Two women with recurrent IVF failure (>10 IVF cycles) were also included. A control set of 1660 WES from oocyte donors was used to control for false-positive discoveries.

Participants/materials, setting, methods

WES at 30X was performed on enrolled women’s gDNA using Illumina short-reads technology. Following annotation, variants were filtered to prioritize putative detrimental variants in genes relevant for oocyte/embryonic development using a previously developed and validated pipeline that minimizes false-positive discoveries. Runs of homozygosity (ROH) within each sample were identified using Refined IBD software. Individual-level single-cell RNAseq (scRNAseq) dataset from 18 human oocytes was used to verify the expression of the identified target genes.

Main results and the role of chance

The variant prioritization pipeline employed identified 1,160 unique variants in 1,017 genes (average per sample 59.9 sd 8.5). 453 variants were private to this study compared to the 1000 Genomes and gnomAD databases, 3% affecting splicing and/or the gene product length. Significant 5-fold enrichment of 41 genes involved in DNA-damage and repair pathways commonly associated with ovarian function/oocyte quality was observed (p < 0.001). TP53/AKT pathway also showed significant 5-fold enrichment for 45 genes (p < 0.001). This finding is consistent with the known relationship between infertility and cell-cycle/cancer genes. Overall, 66.4% (675/1,017; 95%CI:63.4-69.3) of the targeted genes were expressed in MII human oocytes. Two women (9%) were homozygous carriers of missense pathogenic variants in known candidate genes previously associated to oocyte/embryo developmental arrest (TRIP13, chr5_901344_C/T, CADD percentile 0.999; PADI6, chr1_17394384_C/G, CADD percentile 0.999). Remarkably, four additional women were carriers of high-impact variants in JAKMIP1, a member of a recently characterized family of proteins involved in various cellular processes, including cytoskeleton rearrangement, cell polarization, and intracellular transport. High-impact JAKMP1 variants were never observed in the oocyte donor control dataset. JAKMIP1 mRNA was detected in each individual biological replicate of scRNAseq analysis of MII oocytes with a mean of 6 transcripts per million.

Limitations, reasons for caution

Functional analysis is ongoing to validate the newly identified genes, data need to be verified in different ethnicities. Nevertheless, this study demonstrates the establishment of a specific and scalable analytical framework that can be employed for the identification of genetic causes in unexplained infertility cases characterized by defective developmental patterns.

Wider implications of the findings

Scaling up this investigative approach would provide an effective strategy for discovering new genes/pathways in what is considered idiopathic infertility, further defining precision reproductive medicine interventions. Importantly, this study revealed lesions in genetic patterns involved in chronic diseases providing a molecular footprint of the well-established link between infertility and comorbidities.

Trial registration number

none

P–530 The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos

Study question

What is the effect of varying diagnostic thresholds on the accuracy of Next Generation Sequencing (NGS)-based preimplantation genetic testing for aneuploidies (PGT-A)?

Summary answer

When single trophectoderm biopsies are tested, the employment of 80% upper threshold increases mosaic calls and false negative aneuploidy results compared to more stringent thresholds.

What is known already

Trophectoderm (TE) biopsy coupled with NGS-based PGT-A technologies are able to accurately predict Inner Cell Mass’ (ICM) constitution when uniform whole chromosome aneuploidies are considered. However, minor technical and biological inconsistencies in NGS procedures and biopsy specimens can result in subtle variability in analytical results. In this context, the stringency of thresholds employed for diagnostic calls can lead to incorrect classification of uniformly aneuploid embryos into the mosaic category, ultimately affecting PGT-A accuracy. In this study, we evaluated the diagnostic predictivity of different aneuploidy classification criteria by employing blinded analysis of chromosome copy number values (CNV) in multifocal blastocyst biopsies.

Study design, size, duration

The accuracy of different aneuploidy diagnostic cut-offs was assessed comparing chromosomal CNV in intra-blastocysts multifocal biopsies. Enrolled embryos were donated for research between June and September 2020. The Institutional Review Board at the Near East University approved the study (project: YDU/20l9/70–849). Embryos diagnosed with uniform chromosomal alterations (single or multiple) in their clinical TE biopsy (n = 27) were disaggregated into 5 portions: the ICM and 4 TE biopsies. Overall, 135 specimens were collected and analysed.

Participants/materials, setting, methods

Twenty-seven donated blastocysts were warmed and disaggregated in TE biopsies and ICM (n = 135 biopsies). PGT-A analysis was performed using Ion ReproSeq PGS kit and Ion S5 sequencer (ThermoFisher). Sequencing data were blindly analysed with Ion-Reporter software. Intra-blastocyst comparison of raw NGS data was performed employing different thresholds commonly used for aneuploidy classification. CNV for each chromosome were reported as aneuploid according to 70% or 80% thresholds. Categorical variables were compared using Fisher’s exact test.

Main results and the role of chance

In this study, a total of 50 aneuploid patterns in 27 disaggregated embryos were explored. Single TE biopsy results were considered as true positive when they displayed the same alteration detected in the ICM at levels above the 70% or 80% thresholds. Alternatively, alterations detected in the euploid or mosaic range were considered as false negative aneuploidy results. When the 70% threshold was applied, aneuploidy findings were confirmed in 94.5% of TE biopsies analyzed (n = 189/200; 95%CI=90.37–37.22), while 5.5% showed a mosaic profile (50–70%) but uniformly abnormal ICM. Positive (PPV) and negative predictive value (NPV) per chromosome were 100.0% (n = 189/189; 95%CI=98.07–100.00) and 99.5% (n = 2192/2203; 95%CI=99.11–99.75) respectively. When the upper cut-off was experimentally placed at 80% of abnormal cells, a significant decrease (p-value=0.0097) in the percentage of confirmed aneuploid calls was observed (86.5%; n = 173/200; 95%CI=80.97–90.91), resulting in mosaicism overcalling, especially in the high range (50–80%). Less stringent thresholds led to extremely high PPV (100.0%; n = 173/173; 95%CI=97.89–100.00), while NPV decreased to 98.8% (n = 2192/2219; 95%CI=98.30–99.23). Furthermore, no additional true mosaic patterns were identified with the use of wide range thresholds for aneuploidy classification.

Limitations, reasons for caution

This approach involved the analysis of aneuploidy CNV thresholds at the embryo level and lacked from genotyping-based confirmation analysis. Moreover, aneuploid embryos with known meiotic partial deletion/duplication were not included.

Wider implications of the findings: The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos, lowering overall diagnostic accuracy. Hence, a proportion of the embryos diagnosed as mosaic using wide calling thresholds may actually be uniformly aneuploid and inadvertently transferred.

Trial registration number

N/A

The Spanish Family Quality of Life Scales under and over 18 Years Old: Psychometric Properties and Families' Perceptions

BACKGROUND

Family quality of life (FQoL), just like individual quality of life, has become a priority outcome in the policies and services received by persons with intellectual and developmental disabilities (IDD) and their families. Conceptualizing, measuring, and theorizing FQoL has been the object of investigation in recent decades. The goal of this paper is to present a revision of the Spanish Family Quality of Life Scales, the CdVF-E < 18 and the CdVF-E >18, and describe the FQoL of Spanish families with a member with IDD.

METHODS

The sample included a total of 548 families with a member under 18 years old and 657 families with a member over 18. Based on an Exploratory Factor Analysis (EFA) firstly and a Confirmatory Factor Analysis (CFA) secondly, the two scales' psychometric properties were explored.

RESULTS

The CdVF-ER < 18 and the CdVF-ER > 18 comprise 5 dimensions, containing 35 and 32 items, respectively, and they show good validity and reliability. The families obtained a high FQoL score, although some differences exist between the dimensions on which families with children under and over 18 score highest and lowest.

CONCLUSION

The characteristics of the revised scales facilitate their use by professionals, administrations, and services.

Endometrial Liquid Biopsy Provides a miRNA Roadmap of the Secretory Phase of the Human Endometrium

CONTEXT

Endometrial liquid biopsy (ELB) is a minimally invasive alternative for research and diagnosis in endometrial biology.

OBJECTIVE

We sought to establish an endometrial micro ribonucleic acid (miRNA) roadmap based on ELB during the secretory phase of the menstrual cycle in both natural and hormonal replacement therapy (HRT) cycles.

DESIGN

Human ELB samples (n = 58) were obtained from healthy ovum donors undergoing a natural and an HRT cycle consecutively. miRNA profiles were identified using next-generation sequencing (NGS). For functional analysis, messenger ribonucleic acid targets were chosen among those reported in the endometrial receptivity analysis.

RESULTS

The human endometrial secretory phase is characterized by a dynamic miRNA secretion pattern that varies from the prereceptive to the receptive stages. No differences in miRNA profiles were found among natural versus HRT cycles in the same women, reinforcing the similarities in functional and clinical outcomes in natural versus medicated cycles. Bioinformatic analysis revealed 62 validated interactions and 81 predicted interactions of miRNAs differentially expressed in the HRT cycle. Annotation of these genes linked them to 51 different pathways involved in endometrial receptivity.

CONCLUSION

This NGS-based study describes the miRNA signature in human ELB during the secretory phase of natural and HRT cycles. A consistent endometrial miRNA signature was observed in the acquisition of endometrial receptivity. Interestingly, no significant differences in miRNA expression were found in natural versus HRT cycles reinforcing the functional clinical similarities between both approaches.

Diversity of Staphylococcus aureus clones in wild mammals in Aragon, Spain, with detection of MRSA ST130-mecC in wild rabbits

AIMS

To determine the Staphylococcus aureus carriage rate in wild mammals in Aragon, northern Spain, to analyse their antimicrobial resistance phenotype/genotype and to characterize the recovered isolates.

METHODS AND RESULTS

Nasal and rectal swabs of 103 mammals were collected in Aragón during the period 2012-2015. Antimicrobial susceptibility, the presence of antimicrobial resistance genes and virulence factors were investigated. Molecular characterization was carried out by spa, MLST, agr and SCCmec. Staphylococcus aureus were recovered from 23 animals (22%). Four of the 23 S. aureus were methicillin-resistant S. aureus (MRSA). Three MRSA were mecC-positive and were isolated from European rabbits and were typed as t843 (ascribed to CC130). The remaining MRSA was a mecA-carrying isolate from European hedgehog, typed as ST1-t386-SCCmecIVa-agrIII and it harboured the blaZ, erm(C), ant(6)-Ia and aph(3´)-IIIa resistance genes. A high diversity of spa-types was detected among the 19 methicillin-susceptible S. aureus isolates, which showed high susceptibility to the antimicrobials tested. The tst gene and different combinations of staphylococcal enterotoxins were found.

CONCLUSIONS

Staphylococcus aureus were detected in nasal and rectal samples of wild mammals. Wild rabbits could be a reservoir of mecC-MRSA.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work provides information on the presence and characteristics of S. aureus from mammals in a defined geographic region in Spain.

Heterogeneous nuclear ribonucleoprotein C1 may control miR-30d levels in endometrial exosomes affecting early embryo implantation

STUDY QUESTION

Is there a specific mechanism to load the microRNA (miRNA), hsa-miR-30d, into exosomes to facilitate maternal communication with preimplantation embryos?

SUMMARY ANSWER

The heterogeneous nuclear ribonucleoprotein C1 (hnRNPC1) is involved in the internalization of endometrial miR-30d into exosomes to prepare for its subsequent incorporation into trophectoderm cells.

WHAT IS KNOWN ALREADY

Our group previously described a novel cell-to-cell communication mechanism involving the delivery of endometrial miRNAs from the maternal endometrium to the trophectoderm cells of preimplantation embryos. Specifically, human endometrial miR-30d is taken up by murine blastocysts causing the overexpression of certain genes involved in embryonic adhesion (Itb3, Itga7 and Cdh5) increasing embryo adhesion rates.

STUDY DESIGN, SIZE, DURATION

Transfer of maternal miR-30d to preimplantation embryos was confirmed by co-culture of wild-type (WT) and miR-30d knockout (KO) murine embryos with primary cultures of human endometrial epithelial cells (hEECs) in which mir-30d was labeled with specific Molecular Beacon (MB) or SmartFlare probes. Potential molecules responsible for the miR-30d loading into exosomes were purified by pull-down analysis with a biotinylated form of miR-30d on protein lysates from human endometrial exosomes, identified using mass spectrometry and assessed by flow cytometry, western blotting and co-localization studies. The role of hnRNPC1 in the miR-30d loading and transportation was interrogated by quantification of this miRNA in exosomes isolated from endometrial cells in which hnRNPC1 was transiently silenced using small interference RNA. Finally, the transfer of miR-30d to WT and KO embryos was assessed upon co-culture with sihnRNPC1 transfected cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Murine embryos from miR-30d WT and KO mice, (strain MirC26tm1Mtm/Mmjax), were obtained by oviduct flushing of superovulated females. Endometrial Exosomes were purified by ultracentrifugation of supernatants from primary cultures of hEECs or Ishikawa cells. MB and Smartflare miR-30d probes were detected by confocal and/or transmission electron microscopy (TEM). hEECs and exosomes derived from them were subjected to pull-down with a biotinylated form of miR-30d. Captured proteins were identified by mass spectrometry (MS/MS). Western blotting was performed to detect hnRNPC1 and CYR61 in whole lysates, subcellular fractions and secreted vesicles from hEECs. Co-localization studies of the selected proteins with the exosomal marker CD63 were performed. FACS analysis was carried out to determine the presence of hnRNPC1 inside exosomes. Silencing of hnRNPC1 was conducted in the Ishikawa Cell Line with the Smart Pool Accell HNRNPC siRNA at a final concentration of 50 nM. RT-qPCRs were done to determine the messenger levels of miR-30d in cells and exosomes. Co-cultures of WT and KO embryos were established with Ishikawa cells double-transfected with sihnRPNC1 and MB probes.

MAIN RESULTS AND THE ROLE OF CHANCE

MS/MS analysis allowed us to identify hnRNPC1 as a possible protein to influence miR-30d loading into exosomes. Co-localization studies of hnRNPC1 with CD63 and FACS analyses suggested the presence of hnRNPC1 inside exosomes. Silencing of hnRNPC1 in Ishikawa cells resulted in a sharp decrease of the levels of miR-30d in both epithelial-like cells (P = 0.0001) and exosomes (P = 0.0152), suggesting its potential role in miR-30d biogenesis and transfer. Co-culture assays of miR-30d KO embryos with sihnRNPC1 hEECs revealed a decrease in embryo-miR-30d acquisition during the adhesion and invasion stages. In turn, transient silencing of hnRNPC1 results in a significant decrease of blastocyst adhesion compared to mock transfection conditions using Block-it, in both WT [Mean ± SD; 67 ± 10.0% vs. 38 ± 8.5%(P = 0.0006)] and miR-30d KO embryos [Mean ± SD; 50 ± 11.5% vs. 26 ± 8.8% (P = 0.0029) (n = 2); 14 embryos transferred per condition tested].

LARGE-SCALE DATA

MS/MS data are available via ProteomeXchange with identifier PXD008773.

LIMITATIONS, REASONS FOR CAUTION

The Ishikawa Cell Line was used as a model of hEECs in silencing experiments due to the low survival rates of primary hEECs after transfection.

WIDER IMPLICATIONS OF THE FINDINGS

The data show that hnRNPC1 may be involved in the internalization of miR-30d inside exosomes. The decreased rates of embryo adhesion in endometrial epithelial-like cells transiently silenced with sihnRNPC1evidence that hnRNPC1 could be an important player in the maternal-embryo communication established in the early stages of implantation.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by the Miguel Servet Program Type I of Instituto de Salud Carlos III [CP13/00038]; FIS project [PI14/00545] to F.V.; the 'Atracció de Talent' Program from VLC-CAMPUS [UV-INV-PREDOC14-178329 to NB]; a Torres-Quevedo grant (PTQ-13-06133) by the Spanish Ministry of Economy and Competitiveness to IM and MINECO/FEDER Grant [SAF2015-67154-R] to C.S. The authors declare there is no conflict of interest.

How Blind Readers Perceive and Gather Information Written in Braille

This study examined how readers who are blind perceive and retrieve written information and investigated the strategies they used to compensate for their limitations. It found that expert braille readers are not limited to the isolated identification of individual braille characters that are later integrated, but can integrate greater quantities of written information, which indicates that braille reading is a more dynamic and integrated process than has previously been thought.

The Patient's Comorbidity Burden Correlates with the Erectile Dysfunction Severity

OBJECTIVE

To explore the potential relationship between erectile dysfunction (ED), low testosterone levels, and the Charlson Comorbidity Index (CCI).

MATERIAL AND METHODS

Cross-sectional study on patients referred to the andrology unit in 7 Spanish centers. The ED was diagnosed and graded using the International Index of Erectile Function (IIEF-5) score. Total testosterone, the prevalence of each comorbidity, and the CCI were compared between patients with different grades of ED. Besides, the correlation between total testosterone and the CCI score, the influence of each comorbidity, and the ED severity on the CCI was assessed in a multiple linear regression.

RESULTS

The study included 430 men with a mean age of 61 years. The mean CCI was 3.5, and mean total testosterone 15.2 nmol/L; 389 (91%) subjects had some grade of ED: 97 (23%) mild, 149 (35%) mild-to-moderate, 86 (20%) moderate, and 57 (13%) severe. The increase in ED severity was significantly associated with a decrease in total testosterone (P=.002), and an increase in the CCI score (P<.001). Testosterone levels were significantly lower in patients with obesity, diabetes, hypercholesterolemia, and hypertriglyceridemia (P<.05). However, only the prevalence of diabetes and hypertension was significantly associated with the severity of ED. The multivariate analysis including variables related to all assessed comorbidities, total testosterone levels, and the DE severity significantly predicted the CCI score (P<.001, R²=.426). The severity of ED significantly contributed to this model (P=.011), but total testosterone did not (P=.204).

CONCLUSIONS

The CCI is significantly associated with the ED severity, but it shows a weak correlation with the testosterone levels.

Diagnosis of Endometrial-Factor Infertility: Current Approaches and New Avenues for Research

Over the last decade, research to improve success rates in reproductive medicine has focused predominantly on the understanding and optimization of embryo quality. However, the emergence of personalized medicine in ovulation induction and embryology has shifted the focus to assessing the individual status of the endometrium. The endometrium is considered receptive during an individually defined period, the window of implantation (WOI), when the mother permits a blastocyst to attach and implant. This individual receptivity status can now be objectively diagnosed using the endometrial receptivity array (ERA) developed in 2011. The ERA, together with a computational algorithm, detects the unique transcriptomic signature of endometrial receptivity by analyzing 238 differentially expressed genes and reliably predicting the WOI. We and others have illustrated the utility of this personalized diagnostic approach to discriminate between individual physiological variation in endometrial receptivity and unknown endometrial pathology, deemed as causal in recurrent implantation failure (RIF). An international randomized controlled trial ("The ERA as a diagnostic guide for personalized embryo transfer." ClinicalTrials.gov Identifier: NCT01954758) is underway to determine the clinical value of this endometrial diagnostic intervention in the work-up for reproductive care. In this review, we analyse the current clinical practice in the diagnosis of the endometrial factor together with new avenues of research.

The superior mesenteric artery and the variations of the colic patterns. A new anatomical and radiological classification of the colic arteries

The superior mesenteric artery (SMA) supplies irrigation to the small intestine, ascending and a variable area of the transverse colon. Although medical imaging and surgical procedures have been widely developed in the last decades, the anatomy of the SMA using advanced imaging technology remains to be elucidated. Previous studies have used small sample sizes of cadaveric or radiological samples to propose a number of classifications for the SMA. In this study, we aimed to provide a more detailed description and useful classification of the SMA and its main branches [middle colic artery (MCA), right colic artery (RCA), and ileocolic artery (ICA)]. Samples (n = 50, 28 males and 22 females) were obtained from the repository of human cadavers located at the Department of Human Anatomy and Embryology, Complutense University of Madrid. This sample was dissected by preclinical medical students and completed by two of the authors (Gamo and Jiménez). A second set of samples was obtained from a bank of computerized tomography (CT) (560 CTs, 399 males and 161 females) collected by the Radiology Department at the Clínico San Carlos Hospital, Spain. Based on the results obtained from these studies, we propose a new classification of four patterns for the SMA anatomy. Pattern I as the independent origin of the three main branches of the SMA (cadaveric 40 %; CT 73.69 %); Pattern II is subdivided in three sub-patterns based on the common trunks of origin: Pattern IIa, common trunk between RCA and MCA (cadaveric 20 %, CT 4.28 %); Pattern IIb, common trunk between RCA and ICA (cadaveric 32 %, CT 15 %); Pattern IIc, common trunk for the three main branches (cadaveric 0 %, CT 0.35 %); Pattern III, as the absence of RCA (cadaveric 8 %; CT 2.32 %) and Pattern IV, based on presence of accessory arteries (not found in any of the samples). Although the independent origin of the three colic arteries have been classically described as the most frequent, the right colic artery is responsible of major variations.

Hsa-miR-30d, secreted by the human endometrium, is taken up by the pre-implantation embryo and might modify its transcriptome

During embryo implantation, the blastocyst interacts with and regulates the endometrium, and endometrial fluid secreted by the endometrial epithelium nurtures the embryo. Here, we propose that maternal microRNAs (miRNAs) might act as transcriptomic modifier of the pre-implantation embryo. Microarray profiling revealed that six of 27 specific, maternal miRNAs were differentially expressed in the human endometrial epithelium during the window of implantation--a brief phase of endometrial receptivity to the blastocyst--and were released into the endometrial fluid. Further investigation revealed that hsa-miR-30d, the expression levels of which were most significantly upregulated, was secreted as an exosome-associated molecule. Exosome-associated and free hsa-miR-30d was internalized by mouse embryos via the trophectoderm, resulting in an indirect overexpression of genes encoding for certain molecules involved in the murine embryonic adhesion phenomenon--Itgb3, Itga7 and Cdh5. Indeed, this finding was supported by evidence in vitro: treating murine embryos with miR-30d resulted in a notable increase in embryo adhesion. Our results suggest a model in which maternal endometrial miRNAs act as transcriptomic modifiers of the pre-implantation embryo.

Referencias anatómicas para la tenolisis percutánea de los flexores de la mano

Objetivos: La tenosinovitis estenosante de los flexores de la mano es una patología muy frecuente en el ámbito laboral. Se han descrito distintos tratamientos de tipo conservador, aunque el tratamiento definitivo de los casos que no responden a otros tratamientos es quirúrgico, siendo la técnica abierta y la liberación percutánea las dos técnicas de elección. Esta última ha obtenido resultados superiores de satisfacción aunque la ausencia de visualización incrementa las lesiones neurovasculares y el riesgo de apertura incompleta de la polea, por ello es necesario establecer puntos de referencia anatómicos para realizar una correcta liberación.

Material y método: Se realizó un estudio experimental en cinco manos de cadáver en el Departamento de Anatomía de la Universidad de Valladolid. Se realizaron mediciones de las longitudes de los dedos y de la polea. Se registró la posición de la aguja y de cada uno de los dedos al realizar la polectomía percutánea y se comprobó si la sección de la polea A1 fue completa, si existió alguna laceración de los tendones o si se produjo una lesión iatrógena del paquete neurovascular o de la polea A2.

Resultados: Para establecer el punto de entrada de la aguja intramuscular se tomó como referencia la intersección entre el eje del dedo y el surco dígito-palmar. En el caso del tercer y cuarto dedo la entrada fue en el punto de la intersección, mientras que en el resto se desplazó 1-1,5 mm en dirección medial.

El ángulo de entrada de la aguja intramuscular en el plano anterior osciló entre 0-30 grados en función del dígito, mientras que en el plano lateral fue siempre 0 excepto en el cuarto dedo que corresponde a un valor de -60 grados respecto al eje palmar. No se observó ninguna lesión iatrógena de los tendones flexores, del paquete neurovascular o de la polea A2. La apertura fue completa en todos los dedos salvo en un caso del segundo dedo.

Conclusión: La tenolisis percutánea de la polea A1 es una alternativa a la liberación abierta tradicional, aunque existe controversia debido a la relación riesgo-beneficio. El conocimiento de las referencias anatómicas así como la posición exacta del dígito y de los instrumentos utilizados ayudan a evitar la liberación incompleta de la polea, los problemas neurovasculares y la lesión de estructuras adyacente.

En el presente estudio anatómico se ha comprobado que es una técnica segura ya que no ha ocurrido ninguna lesión iatrógena y fiable, que se ha conseguido una liberación completa en todos los casos salvo uno.

Inhibition of Delta-like 4 mediated signaling induces abortion in mice due to deregulation of decidual angiogenesis

OBJECTIVE

To explore whether the Dll4/Notch1 pathway plays a key role in regulating the vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) driven decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype.

METHODS

Progesterone-replaced ovariectomized pregnant mice received a single injection of YW152F (Dll4 blocking antibody, BAb) or placebo at embryonic day (E) 4.5. Animals were sacrificed at different time points; blood and uterus were collected for further analysis. Number of embryos and implantation site, uteri weight, and serum progesterone levels were assessed. Alterations in the tip/stalk phenotype were determined by quantitative immunofluorescent analysis of vascularization, Dll4 expression, cellular proliferation and apoptosis in uterine sections.

RESULTS

Abrogation of Dll4 signaling leads to a promiscuous expression of Dll4, increased cell proliferation, apoptosis and vascularization at E 6.5. Such an abrogation was associated with a dramatic disruption of embryo growth and development starting at E 9.5.

DISCUSSION

The observed promiscuous expression of Dll4 and the increase in cell proliferation, apoptosis and vascularization are events compatible with loss of the tip/stalk phenotype. Excessive (although very likely defective) decidual angiogenesis due to such vascular alterations is the most likely cause of subsequent interruption of embryo development and related pregnancy in Dll4 treated mice.

CONCLUSIONS

Dll4 plays a key role in regulating decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype.

PGE2 and PGF2α concentrations in human endometrial fluid as biomarkers for embryonic implantation

BACKGROUND

Prostaglandin (PG) signaling has been implicated in embryonic implantation in several animal species including humans; however, this knowledge has not yet been clinically translated. The objective of this work is to investigate whether PGE2 and PGF2α in endometrial fluid (EF) can be used as biomarkers of human embryonic implantation.

PATIENTS AND METHODS

Lipidomic profile of human EF (n = 173) obtained through natural cycles, hormonal replacement therapy, controlled ovarian stimulation, and refractory endometrium induced by the insertion of an intrauterine device was analyzed by liquid chromatography and tandem mass spectrometry. Immunohistochemistry, Western blotting, immunolocalization of PG receptors on mouse embryos, embryo adhesion assay, pharmacological interventions, and statistical analysis were conducted.

RESULTS

PGE2 and PGF2α concentrations increased significantly in the human EF during the window of implantation in natural cycles and assisted reproductive technologies patients undergoing in vitro fertilization and ovum donation. This profile was abrogated in the refractory endometrium. We also demonstrated that PGE2 and PGF2α synthases are located in the endometrial epithelium being hormonally regulated during the window of implantation, and PG receptors are expressed in the trophoectoderm and inner cell mass of mouse blastocysts. Using an in vitro model of embryo adhesion, we demonstrated that inhibition of PGE2 and PGF2α or PG receptors (EP2 and FP) prevents embryo adhesion, which can be overcome by adding these molecules back or using their agonists. Finally, in a pilot study, we demonstrated that PGE2 and PGF2α levels from EF 24 hours prior to embryo transfer could predict pregnancy outcome.

CONCLUSIONS

Our results suggest that PGE2 and PGF2α concentrations 24 hours prior to embryo transfer are potential noninvasive biomarkers of endometrial receptivity.

Molecular basis of implantation

The process of embryonic implantation needs coordinated development and communication between the blastocyst and the maternal endometrium. Considerable advances in the understanding of the cell biology of the human embryo and maternal endometrium have been achieved separately. However, the communication between them, and the reciprocal effects on each other, constitute a complicated and yet unsolved question in reproductive medicine that must be further investigated. A paracrine dialogue between the embryo, endometrium and the corpus luteum is known to occur in other species such as rodents and primates. The aim of this work is to present updated information on the embryonic regulation of endometrial epithelial molecules such as adhesion molecules, anti-adhesion molecules, cytoskeletal proteins, chemokines and leptin during the apposition and adhesion phases of human implantation.

First detection of methicillin-resistant Staphylococcus aureus ST398 and Staphylococcus pseudintermedius ST68 from hospitalized equines in Spain

Eight coagulase-positive staphylococci from equines with different pathologies obtained between 2005 and 2011 were investigated. Isolates were characterized by different molecular techniques (spa-, agr-, MLST), and clonal relatedness of strains was investigated by ApaI and SmaI PFGE. Anti-microbial resistance and virulence profiles were determined. Six isolates were identified as Staphylococcus aureus, and two as Staphylococcus pseudintermedius. Of these, four isolates were methicillin-resistant S. aureus (MRSA) ST398 and one S. pseudintermedius was mecA positive and typed as ST68. One MRSA ST398 strain was isolated in 2005 and might be one of the earliest MRSA ST398 descriptions in Spain. All 5 mecA-positive strains were multidrug resistant and were isolated from hospitalized equines. Three MRSA ST398 strains carried the recently described transposon Tn559 within the chromosomal radC gene. The mecA-positive S. pseudintermedius ST68 strain was also multidrug resistant and harboured the erm(B)-Tn5405-like element. This ST68 strain presented a clear susceptible phenotype to oxacillin and cefoxitin regardless of the presence of an integral and conserved mecA gene and mecA promoter, which enhances the need for testing the presence of this gene in routine analysis to avoid treatment failures. These data reflect the extended anti-microbial resistance gene acquisition capacities of both bacterial species and evidence their pathogenic properties. The first detection of MRSA ST398 and S. pseudintermedius ST68 in horses in Spain is reported.

Spanish family quality of life scales: under and over 18 years old

BACKGROUND

Researchers, professionals, and families have shown increasing concern with the family quality of life (FQoL) of people with intellectual disability (ID) and their families. The goals of this research were (a) to explore how Spanish families understand FQoL by developing 2 different measurement tools for families with a member with ID under and over 18 years old, and (b) to provide 2 diagnostic instruments that will be useful for designing action plans.

METHOD

The study comprised 4 stages: (a) focus groups, (b) expert assessment, (c) pilot study, and (d) normalisation and standardisation. The data were collected in 5 regions in Spain, and 1,205 families with a member with ID took part in the normalisation and standardisation of the scales.

RESULTS

Both FQoL scales were consistent and have valid psychometric characteristics.

CONCLUSIONS

The scales have a diagnostic purpose for use in designing action plans aimed at producing significant changes in families' lives.

Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) as a putative human endometrial stem cell marker

The endometrium is recognized for its remarkable regenerative and remodeling capacity. Every month this hormonally regulated organ undergoes cycles of growth (from 0.5-2 to 7 mm), regression and shedding of two-third of the tissue, leading to its monthly renewal that occurs ∼400 times in a woman's reproductive lifetime. Several groups have suggested the existence of a human endometrial somatic stem cell (SSC) population located around the spiral arterioles of the basalis. Different groups have isolated, identified and characterized putative endometrial SSC populations in human endometrium based on the general features of undifferentiated cells, such as slow cycling detected using the 5-bromo-2-deoxyuridine technique or identification of a side population using the Hoechst efflux dye technique. Nevertheless, specific markers to isolate these endometrial SSC have not yet been consistently elucidated. Accumulated evidence based on lineage tracing studies indicates that a surface protein named Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is a marker that can identify SSC in several tissues such as small intestine mucosa (endodermal origin), hair follicles (ectodermal origin) or mature kidney nephrons (mesodermal origin). This protein plays a crucial role in the Wnt/β-catenin signaling system by acting on the self-renewal and maintenance of the SSC population. In this work, we present novel data suggestive of Lgr5 as a putative human endometrial SSC marker, and since this is a mesoderm-derived tissue, these findings reinforce the concept that Lgr5 can be considered a universal SSC marker.

Concentration of Glutathione and Expression of Glutathione Peroxidases 1 and 4 in Fresh Sperm Provide a Forecast of the Outcome of Cryopreservation of Human Spermatozoa

Oxidative stress imbalance potentially leads to damage of the structure of the cell and macromolecules such as plasma membrane components, proteins, and DNA. The plasma membrane of the sperm cell, which has high levels of polyunsaturated fatty acids, renders it particularly sensitive to free radical-mediated attacks. The freezing and subsequent thawing of sperm is a physically stressful process carried out during routine procedures in assisted reproduction techniques, which results in a highly variable and unpredictable reduction in the number of motile sperm cells. Subsequently, oxidative status can positively or negatively affect the motility, viability, and fertilizing capacity of thawed sperm. These effects are counteracted by various oxidative defense enzymes and anti-oxidants such as glutathione peroxidase isoforms GPx1 and GPx4, glutathione reductase (GR), and cellular glutathione (reduced) (GSH). In this way, oxidative status could represent a predictive marker of sperm quality following the freeze-thaw process. This study was based on 56 human sperm samples. We observed direct positive and negative relationships between the postthaw motile sperm recovery rate and GPx1 and GPx4 expression and activity, on the one hand, and GSH concentrations, on the other. No correlation was found between this recovery rate and GR or basic semen parameters. Predictive values clearly demonstrate that, among the molecules analyzed, the most accurate diagnoses result when analyses are conducted for GPx1 and GPx1 messenger RNA expression, GPx1 and GPx4 enzymatic activity, and GSH concentration. In conclusion, a reserve of glutathione, together with GPx expression, is necessary to eliminate free radicals using GSH or a like structural protein and seems to be essential for a good postthaw recovery. These molecules can be employed as indicators of postthaw sperm quality.

Contemporary genetic technologies and female reproduction

BACKGROUND

The Fifth Evian Annual Reproduction (EVAR) Workshop Meeting discussed knowledge regarding contemporary genetics in female reproduction.

METHODS

Specialist reproductive medicine clinicians and geneticists delivered presentations based on published literature and current research. The content of this report is based on the expert presentations and subsequent group discussions that took place during this Workshop.

RESULTS

Numerous ovarian genes with a role in infertility have been identified. Future challenges for genetic screening of patients, such as those with polycystic ovary syndrome, primary ovarian insufficiency or endometriosis, include the identification of high-throughput strategies and how to apply these findings to infertile patients. The identification of high-quality embryos in IVF using objective technologies remains a high priority in order to facilitate single-embryo transfer. Gene expression profiling of cumulus cells surrounding the oocyte, and proteomic and metabolomic approaches in embryo culture media may significantly improve non-invasive embryo quality assessment.

CONCLUSIONS

The way forward in advancing the knowledge of genes involved in reproduction was considered to be through genome-wide association studies involving large numbers of patients. Establishing international collaboration is required to enable the application of such technologies in sufficient numbers of patients.

Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats

OBJECTIVE

To determine the effects of chronic administration of sildenafil citrate on healthy pregnant rats.

DESIGN

In vivo animal experimental study.

SETTING

Fundación IVI-Instituto Universitario IVI, Valencia, Spain.

SAMPLE

Pregnant and non-pregnant Wistar rats exposed to chronic administration of sildenafil.

METHODS

Placental cross-barrier and feto-maternal relationship levels, maternal blood pressure, and haemodymamic effects on uterine arteries were evaluated. The effect of growth on weight and fetal tissues, and on perinatal outcome, was investigated.

MAIN OUTCOME MEASURES

Maternal blood pressure, blood viscosity, vascular indices of uterine arteries and fetal ductus venosus, plasmatic levels of sildenafil, embryo/fetal and litter weights, perinatal/postnatal survival rates.

RESULTS

Sildenafil citrate crossed the placenta. The maternal and fetal levels of sildenafil, and its metabolite desmethyl-sildenafil, demonstrated a positive linear correlation in treated pregnant animals versus controls; a selective maternal hypotensive effect without changes in uterine vascular resistance was noted on days E8 and E11 (embryonic day). The lower pulsatility index of the ductus venosus on day E18 suggests fetal overflow at the end of the pregnancy. Effects on offspring were placental and liver enlargement, and increased fetal weight gain in the second half of pregnancy (irrespective of liver enlargement) and at birth. Perinatal and postnatal survival rates in the sildenafil group remained unaltered. No haemodynamic effects were evident in non-pregnant animals.

CONCLUSIONS

In normotensive rats, sildenafil appears to have a selective effect at the onset of pregnancy, implying increased fetal blood supply, and increased fetal weight, and placental and liver enlargement, but no increased perinatal mortality.

Study of the molecular mechanisms involved in high-level macrolide resistance of Spanish Campylobacter jejuni and Campylobacter coli strains

OBJECTIVES

To investigate the molecular mechanisms involved in the high-level erythromycin resistance of clinical Spanish Campylobacter jejuni and Campylobacter coli strains.

METHODS

Overall susceptibilities of 678 C. jejuni and 119 C. coli strains, collected from 10 Spanish provinces during 2006 and 2007, were determined by Etest. In high-level erythromycin-resistant strains, molecular determinants were studied. The analysis was focused on region V of the 23S rRNA gene, the rplD and rplV ribosomal genes, and the regulatory region of the CmeABC efflux pump.

RESULTS

The global resistance rate to erythromycin was 3.8%. Among the resistant strains, 93% were C. coli and 7% were C. jejuni. The A2075G mutation in the 23S rRNA gene was detected in all of the resistant strains except for two, which carried the A2074G mutation. None of the ribosomal rplD and rplV genes harboured the described mutations that confer resistance to macrolides. Different mutations affecting the regulatory region of the CmeABC efflux pump were also found.

CONCLUSIONS

C. coli strains are clearly more resistant to erythromycin than C. jejuni. The mutation A2075G in the 23S rRNA gene was responsible for the resistance in most of the strains; A2074G was only found in two strains. Further studies are required to ascertain the effect of mutations in the regulatory region of cmeABC. Our data indicate that the rate of resistance was similar to that of other European countries.

Comparative analysis of the germ cell markers c-KIT, SSEA-1 and VASA in testicular biopsies from secretory and obstructive azoospermias

Testicular biopsy is needed to confirm diagnosis in azoospermic patients and to recover spermatozoa, if possible. This report aims to quantitatively analyse the germline markers stage-specific embryonic antigen (SSEA-1), c-KIT and VASA in testicular biopsies with distinct azoospermic aetiologies. Twenty-three testicular biopsies were analysed by flow cytometry and RT-qPCR for c-KIT, SSEA-1 and VASA. In all the Sertoli cell-only (SCO) samples, significantly lower VASA mRNA expression and fewer VASA+ cells were found compared with obstructive controls. Maturation arrest (MA) cases showed significant differences only with the non-mosaic SCO samples when compared for VASA mRNA expression and percentage of VASA+ cells, but not with the mosaics. However, the normalized VASA-KIT parameter obtained by subtracting the percentage of c-KIT+ cells from the percentage of VASA+ cells showed significant differences between the MA and all the SCO samples. RT-qPCR consistently found differences for the VASA expression between SCO mosaic and non-mosaic samples. However, by flow cytometry, only VASA-KIT showed significant differences between them. Conversely, the percentage of SSEA-1+ cells revealed no inter-group differences. In conclusion, testicular biopsies display different expression profiles for c-KIT and VASA depending on the azoospermic aetiology. These results can be used as a complementary tool to create new molecular categories for diagnoses in azoospermic patients, particularly useful to discriminate between mosaic and non-mosaic SCO patients.

Proteomics of embryonic implantation

Implantation is a complex process involving an intricate cascade of molecular interactions between the implanting blastocyst and the receptive endometrium. The molecular basis of endometrial receptivity and the mechanisms by which the blastocyst first adheres to the luminal epithelium and then penetrates into the stroma are only just beginning to be resolved. Advances in "omics" technologies, particularly proteomics and metabolomics, are set to have a major impact on the development of this field. In the wake of this information, novel targets for contraceptive intervention may become apparent.

Endometrial gene expression analysis at the time of embryo implantation in women with unexplained infertility

Successful embryo implantation depends on the quality of the embryo, as well as on the receptivity of the endometrium. The aim of this study was to investigate the endometrial gene expression profile in women with unexplained infertility in comparison with fertile controls at the time of embryo implantation in order to find potential predictive markers of uterine receptivity and to identify the molecular mechanisms of infertility. High-density oligonucleotide gene arrays, comprising 44 000 gene targets, were used to define the endometrial gene expression profile in infertile (n = 4) and fertile (n = 5) women during the mid-secretory phase (day LH + 7). Microarray results were validated using real-time PCR. Analyses of expression data were carried out using non-parametric methods. Hierarchical clustering and principal component analysis showed a clear distinction in endometrial gene expression between infertile and fertile women. In total we identified 145 significantly (>3-fold change) up-regulated and 115 down-regulated genes in infertile women versus controls. Via Database for Annotation, Visualization and Integrated Discovery functional analysis we detected a substantial number of dysregulated genes in the endometria of infertile women, involved in cellular localization (21.1%) and transport (18.8%) and transporter activity (13.1%) and with major localization in extracellular regions (19.2%). Ingenuity Pathways Analysis of the gene list showed dysregulation of gene pathways involved in leukocyte extravasation signalling, lipid metabolism and detoxification in the endometria of infertile women. In conclusion, endometrial gene expression in women with unexplained infertility at the time of embryo implantation is markedly different from that in fertile women. These results provide new information on genes and pathways that may have functional significance as regards to endometrial receptivity and subsequent embryo implantation.